Sparking plug.



Aso

GOTTLOB HONOLD, OF STUTTGART, GERMANY.

' SPARKING PLUG.

Specification of Letters Patent.

Patented Oct. 11, 1910.

Application filed November 5, 1907. Serial No. 400,830.

To all whom it may concern.:

Be it known that I, GOTTLOB HoNoLo, engineer, a subject of the German Emperor, residing at ll Hopnenlaustrasse, Stuttgart,

ermany, have invented certain new and useful Improvements in Sparking Plugs; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to a mode of fixing in place the insulating massy of a sparking plug, the object being to provide a gas-tight joint around said mass, and is illustrated in the accompanying drawings wherein- Figure l is an axial section through the plug before the insulating mass has been finally fixed in place, Fig. 2 is a like view in which the final fixing has been eEected and Fig. 3 is a like view of a modification. In accordance with this invention, the insulating mass is constructedwith a conical portion A which, when the parts are assem` bled, will be concentric with the cylindrical end B of the housing of the plug. Between this conical portion of the insulation and the cylindrical end of the plug housing or body,

fit a ring C having its inner and outer faces converging downwardly whereby it will fit snugly between the insulation and the housing in smooth and intimate contact with both the said elements. After the ring has been driven home, the end of the body or housing is bent over and down upon the ring, as shown at D in Fig. 2, to secure the ring in place.

Preferably the coned surface at A is sufiiciently steep to produce a powerful wedge action between the parts A and C; it is also advantageous that the ring C should be of such a diameter that it ts tightly into the cylinder B, so that the ring alone will hold the insulating mass accurately in place in the plug before the operation of turning or pressing over the edge of the cylinder.

The ring C has the function of (l) keeping the insulatin mass exactly central in the plug, (2) malgring the plugtight to gas under pressure, (3) protecting the insulating mass from damage, since the ring recelves the pressure exerted in turning over the ed e of the cylinder. For fulfilling these fiinctions the material of the ring must be neither too hard nor too soft; as al gas-tight packing the rin requires to be suiiiciently deformable, whe for exact centering and for receiving the mechanical pressure, the material of the ririg should have a certain degree of resistance. Copper, red brass or very soft iron are particularly suitable materials, although the application of other materials does not appear to be eX- cluded. In order fur-ther to protect the insulating mass from damage a second packing ring E (Fig. 3) may be applied, which receives the pressure between the insulating mass and the plug in an axial direction.

The sparking plug constructed according to the invention presents the advantages that it is simple and cheap, and that because of its simplicity it diminishes the possible sources of failure while it maintains its centering and its tightness as well as plugs of more complex construction do.

Having thus described my invention,what

I claim and desire to secure by Letters-Patent is f l. In a sparking plug, the combination of a housing having a cylindrical interior, an insulating body loosely fitting therein and having an outwardly tapering conical portion, a ring having an outer diameter corresponding to the inner diameter of the housing and downwardly converging inner and outer faces, fitting snugly in the wedge shaped annular space about the insulating body, and means to wedge the ring tightly into the said space.

2. In a sparking plug, the combination of a housing having a cylindrical interior, an insulating body loosely fitting therein and having an outwardly tapering conical portion, a ring having an outer diameter corresponding to the inner diameter of the housing and downwardly converging inner and outer faces, fitting snugly in the wedge shaped annular space about the insulating body, and means to permanently wedge the ring tightly into the said space.

3. In a sparking plug, the combination of a housing having a cylindrical interior, an insulating body loosely fitting therein and having an outwardly tapering conical portion, a ring having downwardly converging inner and outer faces, fitting snugly in the wedge shaped annular space about the insulating body, and terminating short of the bottom of the same to leave a free space therein, and means to wedge the ring tightly into contact with the outer face of the insulating' body and the inner face of the housing.

4. 1n a sparking plug, the combination of a housing having a cylindrical recess formed therein, an insulating body loosely fitting therein and having an outwardly tapering conical flange above the bottom of the recess, a heat-resisting gasket between the flan e and the bottom of the recess, a deformab e metallic ring having downwardly converging inner and outer faces fitting as a wedge snugly in the wedge shaped recess about the flange and outside the periphery of the gasket and terminating short of the bottom of the recess, and nonremovable means to force the ring downwardly into intimate contact with the outer face of the insulating body and the inner face of the housing to center the former and to eHect a gas tight packing around the same.

In testimony whereof I have hereunto affixed my signature in the presence of two witnesses.

GOTTLOB HONOLD. Witnesses:

RUDOLF KLEIN, ERNEST ENTERMANN. 

